Use of resin for fuel system parts such as a fuel tank and a tube of automobiles, a canister, a fuel pump module and the like has been considered for a long time to advantageously reduce weight and increase designability. For example, a fluorine-treated high density polyethylene material (JP-B-53-15862) and a multilayer laminate material of ethylene vinyl alcohol copolymer resin (EVOH) and high density polyethylene (JP-A-9-29904) have been proposed for a fuel tank. However, the fluorine treated high density polyethylene material is insufficient in the gasoline barrier property. On the other hand, while the multilayer laminate material of EVOH and high density polyethylene is superior in the gasoline barrier property, since it requires multilayer blow molding, a complicated and expensive molding apparatus needs to be used, which increases molding processing costs. In addition, the freedom of shape and design of the molded product is limited.
Under the circumstances, the development of a material for a fuel system part, which permits molding processing with a conventional molding apparatus, and which is superior in the properties of gasoline barrier property, impact resistance and the like has been strongly demanded.
Meanwhile, since poly-meta-xylylene adipamide has superior oxygen barrier property, it is considered for a material of packaging films (JP-A-51-24682) or multilayer blow molded beverage containers (JP-A-56-64866), and further for a material of a fuel tank made of multilayer hollow formed parts equipped with an inner layer and an outer layer, which comprise high density polyethylene as a main component (JP-A-5-345349, JP-A-6-191296). When it comes to molding with a conventional molding apparatus and use of the resulting product as a fuel system part, however, although a resin composition of a polyphenylene sulfide resin and a polyolefin resin has been proposed (JP-A-6-191296), it has not been put to practical use due to its insufficient gasoline barrier property. The molded products of a poly-meta-xylylene adipamide resin alone are superior in various gas barrier properties, but extremely weak in impact resistance. To improve impact resistance, addition of nylon 66 and ethylene copolymer to a poly-meta-xylylene adipamide resin has been considered (JP-A-58-201845, JP-A-58-206666), but such has not been practiced seemingly because simultaneous achievement of alcohol-containing gasoline barrier property and impact resistance is difficult, which is required of a material for a fuel system part.